1. Field of the Invention
The present invention relates to apparatus for blending and kneading materials, for example dough, for domestic use.
2. Description of the Prior Art
The blending and kneading of ingredients, such as dough, by hand is a time consuming process and with the advent of the machine age, man has made several attempts to facilitate this process. Examples of such prior art blending and kneading devices to form dough which have been developed in an effort to facilitate this process are disclosed in U.S. Pat. Nos. 663,795; 795,082; 1,750,002; 1,778,363; 2,946,299; 3,406,643; 3,503,344; 3,751,013; 3,854,705 and 2,486,126. However, none of these prior art devices provides for a sweeping action of the kneader arm in addition to conventional rotation thereof as the viscosity of the blended ingredients increases in order to enhance this blending and kneading.
A feature of most prior art devices is that the kneader arm rotates about a fixed axis, usually in a fixed vertical position. This has two drawbacks, firstly that proper kneading of the dough is not ensured, and secondly that large forces may be required on occasions to overcome the resistance of a lump of the ingredients.
The present invention provides a motor operated device for domestic use in kneading ingredients, especially dough, in which these drawbacks are overcome by providing a movable mounting for the kneader arm which allows the axis of rotation thereof to move angularly while kneading proceeds.
In accordance with the present invention, apparatus for kneading ingredients comprises an open-topped container for the ingredients to be kneaded into a mixture having an associated viscosity, support means capable of bridging the open top of the container, and interengaging means carried by the container and the support means for removably securing the support means on the container and for resisting forces tending to rotate the support means relative to the container, rotary drive means including an electric motor carried by the support means, and a kneader arm drivable by the drive means for rotation in the container. The kneader arm is supported solely at its upper end by the drive means and is otherwise free for movement relative to the container, and the interengaging means and support means in combination provide a flexible connection between the container and the rotary drive means for enabling the axis of rotation of the kneader arm to sweep over the container bottom during rotation of the kneader arm, such as the viscosity of the mixture of ingredients being kneaded increases.
The interengaging means may be provided exclusively on opposite sides of the container and may be such as to allow rocking movement of the support means about an axis coinciding with the interengaging means. In addition, the interengaging means may allow elevational movement of the support means relative to the container in the region of the interengaging means, whereby the support means can both rise and fall as a whole relative to the container, and can rock about any horizontal axis.
The support means is preferably a lid, and this may be formed of flexible material, such as plastic, for enabling undulating movement of the mounted lid which provides angular movement of the axis of the kneader arm additional to that provided by rocking movement of the mounted lid described above. The use of a flexible lid is optional, however, and the term "flexible connection" as applied to the connection between the container and the rotary drive means is intended to include the situation where the interengaging means provides rocking and/or elevational movement of the lid without flexing of the lid itself. The lid may comprise at least a translucent portion for facilitating visual observation of the blending and kneading occurring within the container and, if desired, may contain an aperture therein, which may also have a removable cover therefor, such as a slidable cover, for enabling the entry of the ingredients into the container therethrough during the blending and kneading. The container peripheral side wall is preferably tapered inwardly to the container closed bottom portion, such as from substantially the mid-height of the side wall to the closed bottom portion, in the direction toward the center axis for enhancing the agglomeration of the ingredients towards the center axis at the container closed bottom portion.
The container may also contain straight side walls in place of the preferred tapered side walls and, accordingly, the eccentric mixing blade preferably comprises a removable blade extension portion for enabling the length of the kneader arm to be suited to containers of different size bottom portions; for example the arm may be used without the extension for tapered side wall containers and with the extension for straight side wall containers.
The aforementioned rotary drive preferably comprises a motor, such as a fractional horsepower motor and gear box for providing an output speed suitable for kneading. The motor is preferably removably mounted on the lid for facilitating cleaning of the lid after use.
To further enhance the blending and kneading operation, the kneader arm preferably has a configuration corresponding to the shape of the container interior thus rolling the ingredients against the container inner wall thereby enhancing dispersal of the ingredients. Thus, as the kneader arm axis moves angularly with movement of the lid, the kneader arm sweeps the ingredients being mixed over the container bottom to further enhance the blending and kneading of the ingredients. The kneader arm may preferably comprise a hook having a plumb center longitudinal mounting portion with an arcuate portion extending therefrom having an eccentric portion at the bottom thereof. This hook eccentric portion is preferably out of plumb with at least two planes whose intersection define plumb center and is angulated with respect to the bottom of the container.